This is a really interesting problem!
David, very nice trick! The problem would be automating hundreds of these doodads… 
The way I would probably handle this would be to create a script which would change the paragraph style on verso pages to one with a right-to-left direction (in CS4) and the appropriate bullet. The recto pages would get a left-to-right direction and another bullet…
(You can use World Tools to set the paragraph directions.)
Harbs
Here's a script (totally untested):
(Change the “names” to what you need.)
var styleName = “Side Heads”;
var rectoStyleName = “Recto Side Head Style”;
var versoStyleName = “Verso Side Head Style”;
var doc = app.docuemnts[0];
var objStyle = doc.objectStyles.item(styleName);
var rectoStyle = doc.paragraphStyles.item(rectoStyleName);
var versoStyle = doc.paragraphStyles.item(versoStyleName);
var anchoredFrames = doc.stories.everyItem().textFrames.everyItem().getElements();
for(var i=0;i<anchoredFrames.length;i++){
var curFrame = anchoredFrames[i];
if(curFrame.appliedObjectStyle != objStyle){continue}
var parentFrame = curFrame.parent.parentTextFrames[0];
if(!parentFrame){continue}
if(parentFrame.parent.side == PageSideOptions.RIGHT_HAND){
curFrame.parentStory.applyParagraphStyle(rectoStyle);
} else {
curFrame.parentStory.applyParagraphStyle(versoStyle);
}
}